"Breeding-back" aims to restore or immitate extinct animals by selective breeding. This blog provides general information, the facts behind myths and news from various projects.

Saturday, 1 June 2013

The various breeding-back efforts

There several
breeding-back efforts concerning a number of species. Some are well-known and
widely publicized, others are not. While some breeding-back results have a
history of several decades, others are incipient since their project started
only some years ago. In this post I am going to give an overview over the three species the most breeding-back efforts focus on. The
history of breeding-back started in the 1920ies, when two zoo directors tried
to revive the Aurochs that died out in 1627, although the polish zoologist
Feliks Pawel Jarocki had a similar idea back in 1835 [1].

For readers who are familiar with breeding-back, this overview probably isn't anything new, but I want to show the main projects or breeds this blog is going to focus on.

There are
multiple breeding-back efforts to reconstruct the (european) Aurochs, Bos primigenius primigenius. It was the first extinct species (actually, wild type of a
species) to become the focus of a breeding-back effort – the well-known
experiment of the brothers Heinz and Lutz Heck back in the 1920s, which will be
the focus of another post. The result, Heck cattle, was considered to be a “new
aurochs” by the Heck brothers and their followers, and is still by some
breeders today [2]. However, this breed has been criticized early on and is in
fact rather different from the aurochs in several aspects [1]. To improve the
aurochs-likeness of some Heck cattle herds, the Arbeitsgemeinschaft
Biologischer Umweltschutz (ABU) in Germany started to cross them with several aurochs-like
breeds in 1996, such as Sayaguesa or the Spanish fighting bull in order to
bring in what is missing in Heck cattle. These new herds are called Taurus
cattle [ 1,2,3]. Taurus cattle are bred in Germany, Hungary and Denmark. They are slenderer, larger and more long-legged than Heck cattle; also their skulls are longer and the horns face forwards. Good Taurus cattle are much more aurochs-like than usual Heck cattle, although strict selection is yet needed to achieve the Aurochs phenotype completely. In 2008, the Tauros Programme (or TaurOs
Project) was formed. It is, besides the Taurus cattle, another project that aims to breed an aurochs effigy that is hardy and robust like other landraces to fit a life in wilderness. They work cattle from Southern and Eastern Europe and Highland cattle.

Apart from
these projects, there are also a few other initiatives that aim to breed cattle
that is propagated as aurochs proxies by their advocates.

The Tarpan,
Equus ferus ferus, (= the western
subspecies of the wild horse) once ranged from Portugal to the Russian steppe
and apparently displayed a number of different phenotypes (I will go into
further details in a later post) [3]. Several breeds are propagated as surviving
or bred-back Tarpans, which is not supported by the data. There are landraces
resembling the Tarpan, or its respective phenotypes, though. The Konik is
certainly the most popular of them (but only one of many), possibly because it
is promoted as the result of an effigy-breeding program (which is actually not
true) [5]. The Heck horse is a derivation of the Konik that on the other hand
is the result of effigy-breeding, but not necessarily more Tarpan-like. Beside those, a number of other less-derived ponies exist that are at least as authentic but do not get the same attention. In a later post, I will go
into greater detail which horse breeds resemble the Tarpan, and it turns out
that the wild horses actually left their traces all over Europe.

The Quagga

The last known living Quagga which died in 1883, displayed the zoologic museum of Amsterdam (Image source: horse-today.de)

Effigy breeding focusing on the Quagga is fundamentally different from effigy-breeding with domestic animals
because there are no surviving descendants of this animal. The Quagga, Equus quagga quagga, was a distinct
subspecies of the plains zebra that was wiped out around 1900. It is famous for
its secondary reduction of striping in its coat, what distinguishes it from all
other zebra species and subspecies. The Quagga Project started in 1987 which
aims so rebred the pelage characteristics by selective breeding for stripe
reduction in a population of modern plains zebras [6,7]. After 25 years of
breeding, the resulting animals do bear resemblance to the Quagga, although the
real Quagga will remain extinct. I will go into much greater detail on the
Quagga Project’s guidelines, arguments and recent results in a later post.

There also were some claims about the rebreeding of the Barbary Lion, Panthera leo leo. This northern subspecies of the lion is extinct in the wild and disappeared in its pure form because of hybridization with other subspecies. There are lions that are considered possible descendants of pure Barbary lions, and the Barbary Lion Project does (or did, I don't know if it is still running) research in order to determine the presence and degree of influence of the true Barbary lion in these living cats. If it really turns out that its genes are still present in a population of lions, breeding-back using genetic screening might restore a pure lineage of this subspecies [8].

As you can see,
there are numerous breeding-back projects and results, but none of these has
produced final results yet that clearly show all the desired features. Effigy-breeding
isn’t easy or to be done quick: there is a precise picture the breed has to
match with AND they have to be genetically diverse AND ecologically potent at
the same time in order to survive as a wild animal in nature. The reasons why until now there is no "perfect" effigy-breed is either that some projects have not been
running long enough yet, or that the breeding was not efficient
enough in other cases. And, not to forget, the final step cannot be made by Man's artificial breeding but takes place when the animals are exposed to natural selection and become wild animals with surviving strategies and adaptions to their habitat.

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About this blog

This blog is on everything related to the so-called “breeding-back” of extinct animals: From the extinct animals themselves, over their often domestic descendants and dedomestication to news and facts about various breeding-back projects, reports and photos from my own breeding-back related trips. I try to have a balanced and fact-based approach to this subject and to dismantle many of the popular myths. Enjoy!

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About me

My major interest always have been extinct animals, from dinosaurs to Pleistocene megafauna and more recent extinctions. Besides that I am interested in evolution, genetics and ecology.
I am also an amateur animal artist, making drawings and models mostly of extinct animals.